Apparatus for recovering placer gold



Jan. 8, 1935. w c HANSON 1,987,475

APPARATUS FOR RECOVERING PLACER GOLD Filed Nov. 5. 1934 2 Sheets-Sheet l INVENTOR:

ATTORNEY.

Jan. 8, 1935. w. c. HANSON 1,937,475

APPARATUS FOR RECOVERING PLACER GOLD Filed Nov. 5, 1934 2 Sheets-Sheet 2 'IIIIIIIIIIII/Il III, villa IIIfII/f/II/IIII/IIIIIIIIII/IIIII/IIIIIlIIIIlII/A 'lIIII/I IIIIIIIIII/I/III INVENTOR: 6. Hanson? ATTORNEY.

iatented Jan. 8, 1935 UNITED STATES PATENT OFFICE APPARATUS FOR RECOVERING PLACER GOLD Walter 0. Hanson, Hillsboro, N. Mex., assignor, by

mesne assignments, to Natural Resource Development Company, Dallas, Tex.

Application November 5, 1934, Serial No. 751,497

9 Claims. (01. 209-12) This invention relates to the recovery and material is known to contain much fine or fiour saving of gold from near surface deposits or gold, but due to its characteristic plasticity and what are more commonly termed placer deposits tenacity when wet, great difiiculty is experienced and the like, and it has to do with a novel appain extracting the gold therefrom. I'he present inratus for economically and profitably saving, vention, therefore, has for one of its main objects 5 more particularly, the fine or fiour gold contained to overcome the natural suction and tenacity of in placer or'so-called low grade deposits; this material in its watered condition, whereby The great problem has been to recover the gold to efiect quickly and inexpensively the recovery from these deposits at a profit and for years of the fine gold therefrom.

efforts have been made for such accomplishment The present invention consists in the method with but little success. Many improvements have as hereinafter described with particularity and been made in the mining, transportation, crushin the apparatus by which the method is carried ing and recovery of gold from the low grade ore into effect, and each also as set forth in the apfound in the quartz or lode mines, and many such pended claims.

is mines that were unprofitable by the old methods In the accompanying drawings, forming part are, with the improvements, now workable on a of this specification, and illustrating more or less well-paying basis. However, small indeed are conventionally in general, but with detail as to the improvements that have heretofore been made certain elements thereof, an apparatus for pracin the recovery and saving of the fine or fiour ticing the method of the invention,

gold from low grade placer deposits. The present Figure 1 is a side elevation of the apparatus; 20 invention, therefore, has been brought about to Figure 2 is a section on the line 2-2, of secure a relatively high saving of the fine or Figure 1; fiour gold and at a greatly minimized cost for Figure 3 is a detail view of the grizzly or initial machinery and operating expense. screening device, detached from the apparatus;

In the preliminary handling of the material Figure 4 is a top plan view of one of the con- 25 to be treated, the material is taken from the decentrating tables; posit in placer mining by surface digging and Figure 5 is a longitudinal section on the line shoveling and afterwards it is carried through 5-5, of Figure 4; stages of initial grading, scouring and washing, Figure 6 is .an inverted or bottom view of the and then concentration for final recovery and concentrating table; 30 saving of the gold for amalgamating, retorting Figure 7 is a fragmentary view, in top plan, and forming it into bars. The methods heretoshowing the discharge end portions of the several fore employed, as hereinbefore stated, have inconcentrating tables in cooperative relation to volved but little improvement and the apparatus the conveyor trough;

used not only has been produced at relatively Figure 8 is fragmentary sectional view on the- 35 high cost but cost of operation has been also high line 8-8, of Figure 7; and and the percentage of gold recovered so small Figure 9 is a section transversely of a conthat the process of recovery has, in most cases, centrating table, taken on the line .9--9, of been unprofitable and so much so that the oper- Figure 5.

no ators have ceased operating. The apparatus as illustrated in the drawings One reason for failure, or at least, unprofitable will now be described. Referring now more paroperation with the processes heretofore followed, ticularly to Figure 1, the numeral 1 designates is the character of the material, particularly an ordinary scoop-shovel or drag-line-bucket by where the clay or caliche formation is enwhich the material from the deposit is taken to countered, as it most invariably occurs in the vast the apparatus. As shown, this shovel or bucket 45 areas, particularly in the placer deposit regions is in elevated position, ready to dump its contents of southwestern United States and Mexico, and onto a grading device 2, which is set at an angle even extending to South America. However, by of approximately forty-five degrees, and, as best the term caliche, as hereinafter used, more illustrated in Figure 3, comprises aframe includ- 59 particularly, is meant a calcareous sedimentary ing end cross-members 3 and spaced bars 4. The deposit, locally namedin Arizona. It is the combars of the device 2 are spaced a considerable pacted residual or alluvial surface deposit, cedistance apart, so that relatively large pieces mented by infiltrated calcareous materiaL'found of material will pass therebetween, while the over extensive areas in the semi-arid regions of over-size pieces or boulders are shunted into a as Mexico and southwestern United States. This chute 5 and discharged from the chute back into the pit from which the material is taken, or, obviously, in some cases, into a special pit or place of reception.

The material passing between the bars 4 of the grizzly or grading device 2, falls into a hopper 6 in which reciprocates a scrubber device or gratelike frame I, above which is located a waterdischarging-nozzle 8 at the end of a water supply pipe 9 having a suitable controlling valve 10.

The washed material and washing water passes through the scrubber device 7 and from the bottom of the hopper 6, through an outlet tube 11, and thence into a further washing and screening device 12, termed a trummel. This device, as shown, comprises a cylindrical outer shell or casing, set at an incline downwardly towards its discharge end, and having rotatable axially therein a cylindrical screen 13 of comparatively fine mesh with respect to the outlet openings through which the larger particled material is removed from the apparatus at the different stages of the treatment.

In the center of the screen 13 is a tubular core member 14, which is apertured throughout, as at 15, and said screen and tubular core member are fixed to rotate together, the core member being journalled rotatably, but with leaktight effect in any approved manner, in the end walls 16 which close the outer cylindrical'shell or casing 12; the outlet tube 11 from the hopper 6 discharging directly into the upper or higher positioned end portion of the tubular core member 14. 1

Material too large to pass through the apertures 15 in the tubular core member 14, are discharged through the core-outlet or mouth 16, onto a chute 17, whence the material so discharged is taken away by any suitable means for such treatment as may be desired. Material passing through the apertures 15 of the tubular core member 14 is carried around in the surrounding screen 13 until finally disintegrated sufficiently to pass through the meshes of the screen, whereupon it is deposited in the longitudinally elongated hopper bottom portion 18 of the cylindrical outer shell or casing 12, at the middle of which is a well or receiving chamber 19.

From the bottom of the well or receiving chamber 19, are a series of discharge pipes 20 leading to positions above the upper or higher positioned end portions of concentrating tables 21, of which there may be one or more in the apparatus, but, as shown, there being six of such tables, each of which is identical in construction and operation. Therefore, only one will be referred to in describing the structure and peculiar operation thereof.

The concentrating table 21 comprises a rectangular, box-like body, having two side and one end wall. In practice the table is set normally at an incline downwardly to its open or discharge end. It is swingably supported by cables 22 at its four corner portions. These cables are relatively short, so that when endwlse movement is imparted to the table it is reciprocated or oscillated thereon, with an arcuate up and down movement during its longitudinal reciprocation. This gives an operative effect to be presently more fully explained, which is an important feature of the invention.

The endwise movement of the table may be accomplished through any suitable or approved instrumentality. As shown, a yoke or Y-shaped element 23 is hingedly attached, as at 24, to the under side of the bottom of the table 21, and at its stem end portion it is swivelled or attached, by a ball-and-socket or other suitable universal joint, 25, to one end of a connecting rod or pitman 26, said rod or pitman being attached at its opposite end to an eccentric 27 by which it is reciprocated and oscillated, and, in turn, efiects the reciprocation and oscillation of the table 21, as hereinbefore described. The eccentric 27, of which there is, of course, one for each table, as shown, is mounted on a shaft 28 journalled in bearings 29 provided therefor on the side member 30 of the base or under-frame of the apparatus, there being one of these shafts on each side of the frame.

The shaft 28 is rotated by sprocket chain gearing 31 from a suitable motor, obviously electrical or of the internal combustion type, as may be most convenient in the locality where the apparatus is operated, and, preferably, as

shown, said motor, designated by the numeral I 32, drives a counter-shaft 33 on the upper portion of the base or under-frame. On this counter-shaft 33 is fixed a toothed gear 34 which meshes with another gear 35 on the inner end portion of the core tube 14 of the trummel 12,

whereby rotation is imparted to said core tube simultaneously with the actuation of the concentrating tables 21. The shaft 33 is also provided with a miter gear 36 which drives a similar gear 37 having a sprocket gear connection 38 with an eccentric 39, said eccentric 39 having a rod or pitman 40 hingedly attached, as at 41, to the initial scrubber device 7, whereby to reciprocate the latter, also simultaneously with the actuation of the trummel and the concentrating tables.

In a box-like concentrating tables 21 mats or carpets 42 of strong, woven, felted or other suitable material of sufficient porosity or absorbent quality that fine or flour gold will work its way into it, are placed in an undulated or corrugated form and arrangement, with looseness in the alternate rises thereof, which portions have placed thereunder transverse cleats 43 or supporting ribs (see Figure 5 of the drawings) which may rest loosely on the bottom of the table or, in some cases, where desirable, they may be fastened to the bottom of the table. At the alternate depressions in the mat or carpet 42 transverse riflies or baflies 44 are located. These riflles or bafiles 44, as shown, are preferably formed integrally with longitudinal side members 45 of a removable frame which is readily placed in and taken from the box-like table 21, at will, or they may obviously be each separate one from another and placed in and taken from the table individually.

The riflles or baflles 44 are of inverted L-shape, and the flange portions 46, at the upper edges thereof are disposed forwardly in the direction of flow and discharge of the watered material delivered into the upper end portions of the downwardly inclined tables 21, as illustrated in v the drawings. It is the forward disposition of these flanges 46 of the riflies or baffles 44, together with the reciprocatory and oscillatory motion imparted to the tables 21 and a pulsating action of nee/347s transverse horizontal axis between each of the riifies or bafiles 44, the forward disposition of the flanges 46 of the elements 44 causing a rolling movement of the material, as indicated by the arrows 47 and looped broken lines 48 in Figure 5 of the drawings. The carpet 42 is also pulsated between the riflies or baflles, thereby creating a counteracting, alternating vacuum or pulling suction and pushing effect upon the particles of the material in the body of water carrying it through the tables from the trummel 12, thereby not only tending to overcome the natural suction of the gold-contained caliche r clay-like material in its plastic and tenacious state, as it is when passing through the tables, but further having the efiect of breaking up and disintegrating the material. Hence, the fine or flour gold is pocketed in the lower corners, in front of the respective rifiles or bafiies 44, to the rear of the rises 49 of the mat or carpet, as indicated by the stippling 50 in Figure of the drawings, the larger particles of the material moving, with the rolling motion as indicated by the arrows 47 and broken lines 48, as it passes successively over the respective riflies or baifies 44, as herein just above described; it being, of course, understood that the watered material is delivered to the tables 21 near their upper or higher positioned receiving end portions.

The fine or flour gold obviously works into the porous or absorbent material of the mat or carpet, which from time to time is removed from the table and the gold absorbed or worked therein is extracted therefrom in any suitable or approved manner. To remove the mat or carpet it is only necessary to lift out the riflle or baflle frame first from the table, and after removal of the frame and mat or carpet the interior of the table may be readily cleaned. In this connection, it may be here noted that with the peculiar form and arrangement of the mat or carpet and the particular shape and disposition of the rifiles or baflles, the fine or flour gold is recovered with relative rapidity from the material passed through the apparatus, and with a very high percentage of saving; and, not only that, the tables may be continuously operated for a much longer time than can the heretofore used concentrating tables of which the inventor of the present method and apparatus is aware,that is to say, the old tables have to be cleaned every hour or two, whereas, the tables of the present invention can operate continuously for approximately twenty hours before cleansing is necessary or desirable. This, in itself, is a distinct economical advantage, in addition to the high efilciency in the process of recovery of the gold, not only that which is washed loose from the sand or particles of hard rock, but, as herein particularly described, the fine or flour gold is taken in exceptionally high percentage from the caliche or clay-like substance.

The residue, tailings, or waste from the several concentrating tables or jigs, as they may be termed, 21, is discharged into a trough or conveyor 51, from which it may be returned to the pit or source from which it was originally taken or to any other desired place or device for retreatment. In this connection it may be here stated, that in some instances, the concentrates and metal taken from the concentrating tables )1 jigs 21 when cleaning them, and also the absorbed gold and material that is. extracted from ;he carpet or mat 42 when it is removed from the ;able or jig, are run through a smaller table or ig of similar construction, arrangement and op- :ration as the tables or jigs 21, before the final panning of the concentrates which is done by experts in that art, prior to the amalgamating, retorting and forming the recovered gold into the usual bricks.

An important advantage in the use of the peculiarly constructed, arranged and operated concentrating table or jig of the present invention is that only a relatively small quantity of water is required for the operation of the tables or jigs in the concentrating. process thereof, whereas, by the use of the old style devices a very large quantity of water was necessary, because of the plasticity of the caliche or clay-like substance and the natural strong suction or retentive tendency thereof which'makes it very difficult, and, in fact, quite impossible with the heretofore used devices to extract but a very small percentage of the fine or flour gold from the substance, hence the necessity for using a relatively large quantity of water in order to lessen the degree of plasticity of the base substance, or, in other words, to make the substance more nearly fluid or liquid. By the peculiar construction and arrangement of the tables or jigs 21 of the present invention, the caliche or clay-like substance is effectively broken up or disintegrated to a larger degree than is possible in the old type of table or jig, and, furthermore, the rolling motion imparted to the stream of water embodied material passing through the concentrating device by the peculiar and novel disposition of the flanges 46 of the rifiles 44, augmented by the alternating pulling suction and pushing of the pulsating carpet or mat 42, overcomes the natural retentive suction of the plastic material, whereby, as hereinbefore pointed out, an exceedingly high percentage of the gold is quickly recovered and, too, the tables may be operated continuously for a much longer time than the heretofore used tables before it becomes necessary to cleanse them.

The steps of the process of the present invention may be generally described as initially grading and washing the material as taken from the deposit, and passing the graded and washed material in a body of the washing water or liquid through a concentrating table or jig and subjecting the material, while so passing, to the pulsating action of a bottom carpet or mat and between riflles or baflles having forwardly projecting upper flange portions or means for creating a rolling motion of the watered or liquid embodied material from one rifle or baflle to the next riflie or bafie ahead,. downwardly behind that riflle or baflle, thence rearwardly towards the bottom of the table or jig and upwardly and forwardly from the rearward riflie or bafile, and successively thus over the forward riflles or bafiles to the discharge end of the table or jig.

Obviously, the apparatus for carrying the method or process into effect may be varied in many respects as to construction and arrangement, within the spirit and scope of the invention as herein set forth and claimed, and, therefore, the invention is not limited to the specific construction and arrangement of apparatus shown in the accompanying drawings.

What is claimed is:

1. A concentrating device, for the purposes described, comprising a reciprocatoiy table, a mat located in the lower portion of the table and provided with spaced supporting means to hold it in an undulated or corrugated formation, and bafiies extending transversely of the table and located above the respective depressed portions of the mat and in substantial engagement therewith,

the rises of the mat between the respective bafiies being sufiiciently loose to pulsate with the reciprocation of the table.

2. A concentrating device for the purposes described, comprising a reciprocatory table, a mat located on the table and provided with spaced supporting means to hold it in an undulated or corrugated formation, and baffles extending across the table and located above the respective depressed portions of the mat and in substantial engagement therewith, the rises of the mat between the respective bafiles being sufficiently loose to pulsate with the reciprocation of the table.

3. A concentrating device for the recovery of gold and the like from finely divided material containing the same, comprising a box-like reciprocatory table, a mat located in the lower portion of the table, and provided with spaced supporting means to hold it in an undulated or corrugated formation, and baflles extending transversely across the table and located above the respective depressed portions of the mat and in substantial engagement therewith, the rises of the mat between the respective bafiies being sufficiently loose to pulsate with the reciprocation of the table.

4. A concentrating device for the recovery of gold and the like from finely divided material containing the same, comprising an inclined reciprocatory table, a mat located in the lower portion of the table, and provided with spaced supporting means'to hold it in an undulated or corrugated formation, and bafiles extending transversely across the table and located above the respective depressed portions of the mat and in substantial engagement therewith, the rises of the mat between the respective bafiles being sufficiently loose to pulsate with the reciprocation of the table.

5. A concentrating device for the recovery of gold and the like from finely divided -rnaterial containing the same, comprising an inclined reciprocatory table, a mat located in the lower portion of the table, and provided with spaced supporting means to hold it in an undulated or corrugated formation, and baflles extending transversely across the table and located above the respective depressed portions of the mat and in :ubstantial engagement therewith, the rises of the mat between the respective baflles being sulficiently loose to pulsate with the reciprocation of the table, said baflles having flanges at their upper portions extending in the direction of downward inclination of the table.

6. In an apparatus for recovering goldfrom placer deposits and the like, a concentrating device comprising a downwardly inclined, longitudinally reciprocable table having side walls and. one end wall, the open end being lowermost, an undulatingly arranged mat at the bottom of said table provided with spaced supporting means to hold it, and transverse bafiles extending from side wall to side wall of the table and being remeans for initially grading, washing and scrubbing the material, means for screening and disintegrating the washed material in a body of the washing material, and a concentrating device arranged to receive the water embodied material from said screening and disintegrating means, said concentrating apparatus comprising an inclined reciprocatory table, a mat located in the lower portion of the table, and provided with spaced supporting means to hold it in an undulated or corrugated formation, and battles extending transversely across the table and located above the respective depressed portions of the mat and in substantial engagement therewith, the rises of the mat between the respective baffles being sufiiciently loose to pulsate with the reciprocation of the table.

8. An apparatus for recovering gold and similarly heavy precious metal from material taken from placer deposits and the like, comprising means for initially grading, washing and scrubbing the material, means for screening and disintegrating the washed material in a body of the washing material, and a concentrating device arranged to receive the water embodied material from said screening and disintegrating means, said concentrating apparatus comprising an inclined reciprocatory table, a mat located in the lower portion of the table, and provided with spaced supporting means to hold it in an undulated or corrugated formation, and baffles extending transversely across the table and located above the respective depressed portions of the mat and in substantial engagement therewith, the rises of the mat between the respective bafiles being sufliciently loose to pulsate with the reciprocation of the table, said baflies having flanges at their upper portions extending in the direction of downward inclination of the table.

9. In combination, a reciprocatory concentrating table with a generally flat top, a canvas covering therefor, means to reciprocate the table, means on the table to support the canvas so as to form a series of alternately positioned transversely extending rises and depressions, the depressed portions of the canvas resting on the table, and the supporting means arranged to support the side portions of the rises so as to be free to flex upwardly and downwardly slightly during reciprocation of the concentrating table, and transversely extending bars positioned over the depressions and having their lower edges adjacent the top of the canvas.

' WALTER C. HANSON. 

